The earth observation satellite “Sentinel-6 Michael Freilich” will provide the public with the most accurate measurement data to date on sea level height from Tuesday. The responsible space agencies NASA and ESA announced this and speak of data of unprecedented accuracy.
The step was preceded by more than six months of calibrations – the satellite was launched on November 21st. It is part of ESA’s extremely successful Copernicus program and has been taking sea level measurements for more than 30 years. For the mission, ESA and NASA are cooperating with the US weather and oceanography authority NOAA and the European weather satellite operator Eumetsat.
Measure the global sea level to the nearest centimeter
Sentinel-6 Michael Freilich is named after a former NASA director for earth observation and is intended to precisely measure changes in sea level as a serious consequence of climate change and, among other things, to provide information for weather forecasts. The measurements now collected by satellite altimetry are to be made available in two data sets: The first should be available only hours after the measurement and be accurate to 5.8 centimeters, the second needs two days to be processed and is then accurate to 3.5 centimeters explains NASA. In the course of the year, a data set is to follow that is accurate to 2.9 centimeters and is intended, for example, for climate researchers. About 90 percent of the earth’s oceans are covered.
The satellite is the first of two planned to make up the Copernicus Sentinel-6 / Jason-CS program. The second – Sentinel-6B – is scheduled to start in 2025. ESA and NASA are thus following the ocean observation missions TOPEX / Poseidon (1992), Jason-1 (2001), OSTM / Jason-2 (2008) and Jason-3 (2016). Sentinel-6 Michael Freilich is now at the same altitude as Jason-3 so that he has the same view of the oceans, as the ESA puts it. It has been determined that the difference between the data from the two satellites is less than two millimeters. The data from Sentinel-6 will now be processed at Eumetsat in Darmstadt and then made available.
The background to the missions, which have been successful for decades, is the rise in sea levels as one of the greatest threats worldwide as a result of global climate change. The Intergovernmental Panel on Climate Change (IPCC) assumes that, with unchecked climate change, this could be more than a meter by the end of the century. As a result, coastal cities could be regularly under water, hurricanes and storm surges could increase, and low-lying islands could disappear completely in the sea.